Yeah, I don't think you can ever read anything that can help you write a good screenplay. Reading screenplays would probably be better than any book by some schmoe that's looking to make a buck.

It's like reading a book on how to draw. You either got it or you don't.

I'm mostly looking for pointers about format and structure and whatnot. Seeing some basic advice directly stated might help me. I've written shorts, but never a feature. I'm going to write a treatment and develop the story all the way through before writing out the screenplay.

McKee's "Story" is the greatest, as long as you don't take it too literally. You have to think of it like jazz; learn all the theory, internalize it, then forget it all and just write. And get screenwriting software. Final Draft is fine, I use one called Sophocles which is smaller and quicker and less MS Word-like. I highly recommend it.

I heard "three use of a knife" and "save the cat" are both pretty good.I think ultimately just anything that gives you the confidence to keep on doing whatever you're doing is good. If it's an instructional book, then so be it. The best screenplays come from the intensity of the writer and sometimes it's hard to maintain it unless you have someone telling you that you're on the right track or wrong track or whatever. Otherwise, most of these books are actually quite irrelevant and cannot be approached with anything that resembles reverence. Just reference them when you feel stuck. They cannot be taken seriously; they're like horoscopes that way.

stay far far far away from syd field though. he was the first i ever read -- a laughable "foundation"

I can't say enough bad things about Syd Field. Syd Field is to terrible, formulaic screenwriters what Ayn Rand is to douchey libertarians. Or what Vampire Weekend is to sweater-wearing hipsters. I'm not a fan, in case that wasn't clear.

Syd Field backtracks films into formula, essentially, and asserts that by simply realizing this formula, you will write a good screenplay. It's like saying a pop song goes intro - verse - chorus - verse - chorus - bridge - chorus. Plenty of songs are written like that, but that doesn't make you able to write songs any better.

Plus, everything he's got to say is really just baby shit compared to Joseph Campbell and the Hero's Journey. Read that. I also recently bought "Your Screenplay Sucks" because it's really more of a checklist of things ranging from formatting to story to character to readability, the last of which is pretty interesting.

As far as screenplays go, there's a series called The Shooting Script (a misnomer since they really aren't shooting scripts half the time), and they have films like Juno, Eternal Sunshine, and Michael Clayton. Do yourself a favor and read the script for Michael Clayton, it's killer. Eternal Sunshine is surprisingly boring and wordy for a script, but it reads more like a book anyway.

That being said, just practicing writing is probably the best thing you could do.